Department of Animal and Poultry Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, United States.
Faculdade de Zootecnia e Engenharia de Alimentos, Universidade de São Paulo, Brazil.
Meat Sci. 2018 Mar;137:85-91. doi: 10.1016/j.meatsci.2017.11.009. Epub 2017 Nov 7.
The experiment was conducted to identify the mitochondrial protein responsible for enhancing glycolytic flux. We hypothesized that mitochondrial F-ATPase promotes ATP hydrolysis and thereby the flux through glycolysis. Porcine longissimus muscle mitochondria were incorporated into an in vitro system designed to recapitulate postmortem glycolysis with or without Na-azide to specifically inhibit the β-subunit of mitochondrial F-ATPase that catalyzes ATP hydrolysis. Addition of mitochondria enhanced ATP hydrolysis, glycogen degradation, lactate accumulation, and pH decline in the in vitro system. However, the majority of mitochondria-mediated enhancement in glycolytic flux was abolished in the presence of Na-azide. To investigate further, myofibrillar and mitochondrial proteins were added to the in vitro system after 240min from the initiation of the reaction. Greater pH decline and lactate accumulation were observed in system containing mitochondrial protein compared to their myofibrillar counterpart. In conclusion, mitochondrial F-ATPase is capable of increasing glycolytic flux through promoting greater ATP hydrolysis at lower pH.
该实验旨在鉴定负责增强糖酵解通量的线粒体蛋白。我们假设线粒体 F-ATP 酶促进 ATP 水解，从而促进糖酵解通量。猪背最长肌线粒体被纳入体外系统，旨在模拟死后糖酵解，加入或不加入 Na-叠氮化物以特异性抑制催化 ATP 水解的线粒体 F-ATP 酶的β亚基。添加线粒体可增强体外系统中的 ATP 水解、糖原降解、乳酸积累和 pH 值下降。然而，在存在 Na-叠氮化物的情况下，大多数由线粒体介导的糖酵解通量增强被消除。为了进一步研究，在反应开始 240 分钟后将肌原纤维和线粒体蛋白添加到体外系统中。与肌原纤维蛋白相比，含有线粒体蛋白的系统中观察到更大的 pH 值下降和乳酸积累。总之，线粒体 F-ATP 酶能够通过在较低 pH 值下促进更大的 ATP 水解来增加糖酵解通量。
